Carbon nanomaterials such as carbon nanotubes (CNTs) are useful in electrochemical systems such as fuel cells, batteries, electrochemical capacitors, and electrical energy storage (EES) devices. Fibrous morphologies of carbon nanomaterials offer different capabilities compared to their planar counterparts, particularly for flexible electrochemical devices.
Conventional flexible EES devices with fiber-like geometries are fabricated by twisting the conductive strands (electrodes) together. However a potential drawback associated with this construction is that the twisted electrode fibers may cause non-uniform current and electric potential distributions due to the helical interaction between the two electrodes. Such non-uniform currents can lower cell efficiencies due to the poor utilization of the electrode materials, decrease cycle life because of the detrimental effects of non-uniform stresses on electrode stability, and induce local hot-spots.
It therefore would be desirable to provide new and improved flexible EES or other electrochemical devices that are capable of ameliorating some or all of the foregoing disadvantages. In particular, it would be desirable for the devices to be able to maintain high volumetric energy and power densities during electrochemical device deformations.